This STTR Phase I research will develop detection methods using allosteric DNAzymes (aptazymes) to detect cyanobacterial toxins that occur throughout the world in both fresh and brackish water. Cyanotoxins present a public safety hazard through contamination of drinking water supplies by blue-green algae (cyanobacteria), and sensitive detection of cyanotoxins has been a long-standing challenge. Although instrumented and immunological methods have been developed, a fast and accurate detection kit with high sensitivity and selectivity is still not available and its development would be very desirable. DzymeTech Inc. and the laboratories at the University of Illinois have previously developed many functional DNA-based sensors for metal ions and small molecules such as cocaine. In this research, a related combinatorial selection method will be used to obtain DNAzymes that are allosterically activated by cyanobacterial toxins. By attaching fluorophore-quencher pairs or gold nanoparticles to the DNA, practical sensors that target cyanobacterial toxins will be generated. Successful completion of this Phase I project will establish the feasibility of using nucleic acids to recognize cyanotoxins and thus have broad impact on a number of fields such as medical diagnostics, bioorganic chemistry, and nanotechnology. Aptazyme-based cyanobacterial toxin sensors will have substantial commercial value. Improved cyanotoxin sensors are urgently needed for rapid response to cyanobacterial outbreaks. These sensors will allow government agencies to make rapid judgments about treatment options and will allow the general public to have safer drinking water. The identification of aptazymes that can recognize cyanotoxins will also broaden our fundamental knowledge of interactions between nucleic acids and small molecules.
